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Future aircraft will make more and more use of automated electric power system management onboard. Different solutions are currently being explored, and in particular the use of a supercapacitor as an intelligent energy storage device is addressed in this paper. The main task of the supercapacitor is to protect the electric generator from abrupt power changes resulting from sudden insertion or disconnection of loads or from loads with regenerative power capabilities, like electromagnetic actuators. A controller based on high-gain concepts is designed to drive a DC/DC converter connecting the supercapacitor to the main electric bus. Formal stability proofs are given for the resulting nonlinear system, and strong robustness results from the use of high-gain and variable structure control implementation. Moreover, detailed simulations including switching devices and electrical parasitic elements are provided for different working scenarios, showing the effectiveness of the proposed solution.

Management success of urban water bodies depends on public perceptions among other factors, because opinions and attitudes can be used to identify problems and also to evaluate the implementation of rehabilitation programs. The aim of this study was to explore the environmental perception of residents living along streams of one of the most polluted watersheds in Buenos Aires (Argentina) in view of future rehabilitation programs. During 2012 and 2013, 276 door-to-door surveys were carried out randomly and were analyzed regarding two perspectives: differences in perception with respect to (1) their position in the watershed, and (2) the distance from the watercourses where they reside. In general, residents' perceptions were highly influenced by what they saw or smelled. Although they did not value the watercourses for their wildlife or scenery and did not use them for recreation, they would like them to be improved. Three main topics were relevant: (1) the type of experience they had with the streams near their homes, (2) the recognition that riverbanks have a potential for recreation, and (3) the desire and individual commitment to improve the critical environmental condition. These results have implications for environmental management and, particularly, for the implementation of riparian rehabilitation projects. [ABSTRACT FROM AUTHOR]